Base station apparatus, terminal apparatus, communication method, and integrated circuit

ABSTRACT

To efficiently transmit CSI. A receiver configured to receive a physical downlink control channel for conveying downlink control information including a first information field and a transmitter configured to report channel state information (CSI) are included, wherein the first information field indicates first information, the first information indicates one of multiple states, each of the multiple states is associated with a configuration related to one or multiple CSI reports and a configuration related to one or multiple CSI resources, and the one of the multiple states is configured to be associated with a first serving cell and a bandwidth part (BWP) of the first serving cell.

TECHNICAL FIELD

The present invention relates to a base station apparatus, a terminalapparatus, a communication method, and an integrated circuit. Thisapplication claims priority based on JP 2018-2524 filed on Jan. 11,2018, the contents of which are incorporated herein by reference.

BACKGROUND ART

Technical studies and standardization of Long Term Evolution(LTE)-Advanced Pro and. New Radio (NR) technology, as a radio accessscheme and a radio network technology for fifth generation cellularsystems, are currently conducted by the Third Generation PartnershipProject (3GPP) (NPL 1).

The fifth generation cellular system requires three anticipatedscenarios for services: enhanced Mobile BroadBand (eMBB) which realizeshigh-speed, high-capacity transmission, Ultra-Reliable and Low LatencyCommunication (URLLC) which realizes low-latency, high-reliabilitycommunication, and massive Machine Type Communication (mMTC) that allowsa large number of machine type devices to be connected in a system suchas Internet of Things (IoT).

CITATION LIST Non Patent Literature

NPL 1: RP-161214, NTT DOCOMO, “Revision of SI: Study on New Radio AccessTechnology”, June 2016

SUMMARY OF INVENTION Technical Problem

An object of an aspect of the present invention is to efficientlyprovide a terminal apparatus, a base station apparatus, a communicationmethod, and an integrated circuit by the base station apparatus and theterminal apparatus in the above-mentioned radio communication systems,

Solution to Problem

(1) To accomplish the object described above, aspects of the presentinvention are contrived to provide the following measures. Specifically,a terminal apparatus according to an aspect of the present inventionincludes; a receiver configured to receive a. physical downlink controlchannel for conveying downlink control information including a firstinformation field; and a transmitter configured to report channel stateinformation (CSI), wherein the first information field indicates firstinformation, the first information indicates one of multiple states,each of the multiple states is associated with: a configuration relatedto one or multiple CSI reports; and a configuration related to one ormultiple CSI resources, and the one of the multiple states is configuredto be associated with a first serving cell and a bandwidth part (BWP) ofthe first serving cell.

(2) A base station apparatus according to an aspect of the presentinvention includes; a. transmitter configured to transmit a physicaldownlink control channel for conveying downlink control informationincluding a first information field; and a receiver configured toreceive a channel state information (CSI) report, wherein the firstinformation field indicates first information, the first informationindicates one of multiple states, each of the multiple states isassociated with: a configuration related to one or multiple CSI reports;and a configuration related to one or multiple CSI resources, and theone of the multiple states is configured to be associated with a firstserving cell and a bandwidth part (BWP) of the first serving cell.

(3) A communication method according to an aspect of the presentinvention is a comnumication method for a terminal apparatus, thecommunication method including the steps of: receiving a physicaldownlink control channel for conveying downlink control informationincluding a first information field; and reporting channel stateinformation (CSI), wherein the first information field indicates firstinformation, the first information indicates one of multiple states,each of the multiple states is associated with: a configuration relatedto one or multiple CSI reports; and a configuration related to one ormultiple CSI resources, and the one of the multiple states is configuredto be associated with a first serving cell and a bandwidth part (MVP) ofthe first serving cell.

(4) A communication method according to an aspect of the presentinvention is a communication method for a base station apparatus, thecommunication method including the steps of: transmitting a physicaldownlink control channel for conveying downlink control informationincluding a first information field; and reporting channel stateinformation (CSI), wherein the first information field indicates firstinformation, the first information indicates one of multiple states,each of the multiple states is associated with: a configuration relatedto one or multiple CSI reports; and a configuration related to one ormultiple CSI resources, and the one of the multiple states is configuredto be associated with a first serving cell and a bandwidth part (BWP) ofthe first serving cell.

(5) An integrated circuit according to an aspect of the presentinvention is an integrated circuit mounted on a terminal apparatus, theintegrated circuit including: a receiving unit configured to receive aphysical downlink control channel (PDCCH) for conveying downlink controlinformation (DCI) including a first information field (CSI requestfield); and a transmitting unit configured to report channel stateinformation (CSI), wherein the first inthrmation field indicates firstinformation, the first information indicates one of multiple states,each of the multiple states is associated with: a configuration relatedto one or multiple CSI reports; and a configuration related to one ormultiple CSI resources, and the one of the multiple states is configuredto be associated with a first serving cell and a bandwidth part (BWP) ofthe first serving cell.

(6) A communication method according to an aspect of the presentinvention is an integrated circuit mounted on a base station apparatus,the integrated circuit including: a transmitting unit configured totransmit a physical downlink control channel (PDCCH) for conveyingdownlink control information (DCI) including a first information field(CSI request field); and a receiving unit configured to receive achannel state information (CSI) report, wherein the first informationfield indicates first information, the first information indicates oneof multiple states, each of the multiple states is associated with: aconfiguration related to one or multiple CSI reports; and aconfiguration related to one or multiple CSI resources, and the one ofthe multiple states is configured to be associated with a first servingcell and a bandwidth part (BWP) of the first serving cell.

Advantageous Effects of Invention

According to the present invention, a base station apparatus and aterminal apparatus can efficiently communicate with each other.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a diagram illustrating a concept of a radio communicationsystem according to the present embodiment.

FIG. 2 is a diagram illustrating a schematic configuration of a downlinkslot according to the present embodiment.

FIG. 3 is a diagram illustrating a relationship between a subframe and aslot and a mini-slot in a time domain.

FIG. 4 is a diagram illustrating examples of a slot or a subframe.

FIG. 5 is a diagram illustrating an example of beamforming.

FIG. 6 is a diagram illustrating an example of a configuration of anaperiodic CSI report.

FIG. 7 is a diagram illustrating an example of a configuration of anaperiodic CSI report.

FIG. 8 is a diagram illustrating an example of a configuration of anaperiodic CSI report in a case that multiple serving cells areconfigured.

FIG. 9 is a schematic block diagram illustrating a configuration of theterminal apparatus 1 according to the present embodiment.

FIG. 10 is a schematic block diagram illustrating a configuration of abase station apparatus 3 according to the present embodiment.

DESCRIPTION OF EMBODIMENTS

Embodiments of the present invention ill be described below.

FIG. 1 is a conceptual diagram of a radio communication system accordingto the present embodiment. In FIG. 1, the radio communication systemincludes terminal apparatuses 1A to 1C and a base station apparatus 3.Each of the terminal apparatuses 1A to 1C is hereinafter also referredto as a terminal apparatus 1.

The terminal apparatus 1 is also referred to as a user terminal, amobile station apparatus, a communication terminal, a mobile device, aterminal, User Equipment (UE), and a Mobile Station (MS). The basestation apparatus 3 is also referred to as a radio base stationapparatus, a base station, a radio base station, a fixed station, aNodeB (NB), an evolved NodeB (eNB), a Base Transceiver Station (BTS), aBase Station (BS), an NR NodeB (NR NB), NNB, a Transmission andReception Point (TRP), or gNB.

In FIG. 1, in a radio communication between the terminal apparatus 1 andthe base station apparatus 3, Orthogonal Frequency Division Multiplexing(OFDM) including a Cyclic Prefix (CP), Single-Carrier Frequency DivisionMultiplexing (SC-FDM), Discrete Fourier Transform Spread OFDM(DFT-S-OFDM), or Multi-Carrier Code Division Multiplexing (MC-CDM) maybe used.

In FIG. 1, in the radio communication between the terminal apparatus 1and the base station apparatus 3, Universal-Filtered Multi-Carrier(UFMC). Filtered OFDM (F-OFDM), Windowed OFDM, or Filter-BankMulti-Carrier (FBMC) may be used.

Note that the present embodiment will be described by using OFDM symbolwith the assumption that a transmission scheme is OFDM, but use of anyother transmission schemes described above is also included in thepresent invention.

In FIG, 1, in the radio communication between the terminal apparatus 1and the base station apparatus 3, the CP may not be used, or theabove-described transmission scheme with zero padding may be usedinstead of the CP. The CP or zero passing may be added both forward andbackward.

In FIG. 1, in a radio communication between the terminal apparatus 1 andthe base station apparatus 3, Orthogonal Frequency Division Multiplexing(OFDM) including a Cyclic Prefix (CP), Single-Carrier Frequency DivisionMultiplexing (SC-FDM), Discrete Fourier Transform Spread OFDM(DFT-S-OFDM), or Multi-Carrier Code Division Multiplexing (MC-CDM) maybe used.

In FIG. 1, the following physical channels are used for the radiocommunication between the terminal apparatus 1 and the base stationapparatus 3.

-   -   Physical Broadcast CHannel (PBCH)    -   Physical Downlink Control CHannel (PDCCH)    -   Physical Downlink Shared CHannel (PDCCH)    -   Physical Uplink Control CHannel (PDCCH)    -   Physical Uplink Shared CHannel (PUSCH)    -   Physical Random Access CHannel (PRACH)

The PBCH is used to broadcast essential information block ((MasterInformation Block (MIB), Essential Information Block (EIB), andBroadcast Channel (BCH)) which includes essential information needed bythe terminal apparatus 1.

The PBCH may be used to broadcast a time index within a period of ablock of a synchronization signal (also referred to as an SS/PBCHblock), Here, the time index is inthrmation for indicating the index ofthe synchronization signal and the PBCH within the cell. For example, ina case that the SS/PBCH block is transmitted by using three transmitbeams (transmission filter configuration, Quasi-CoLocation (QCL) forreception spatial parameters), the order of time within a predeterminedperiod or within a configured period may be indicated. The terminalapparatus may recognize a difference in the time index as a differencein the transmit beam.

The PDCCH is used to transmit (or carry) Downlink Control information(DCI) in downlink radio communication (radio communication from the basestation apparatus 3 to the terminal apparatus 1). Here, one or morepieces of DCI (which may be referred to as DCI formats) are defined fortransmission of the downlink control information. In other words, afield for the downlink control information is defined as DC1 and ismapped to information bits,

For example, the following DCI formats may be defined.

-   -   DCI format 0_0    -   DCI format 0_1    -   DCI format 1_0    -   DCI format 1_1    -   DCI format 2_0    -   DCI format 2_1    -   DCI format 2_2    -   DCI format 2_3

DCI format 0_0 may include information for indicating schedulinginformation of the PUSCH (frequency domain resource allocation and timedomain resource allocation).

DCI format 0_1 may include information for indicating schedulinginformation of the PUSCH (frequency domain resource allocation and timedomain resource allocation), information for indicating a BandWidth Part(BWP), a Channel State Information (CSI) request, a Sounding ReferenceSignal (SRS) request, and information related to an antenna port.

DCI format 1_0 may include information for indicating schedulinginformation of the PUSCH (frequency domain resource allocation and timedomain resource allocation).

DCI format 1_1 may include information for indicating schedulinginformation of the PUSCH (frequency domain resource allocation and timedomain resource allocation), information for indicating a BandWidth Part(BWP), Transmission Configuration Indication (TCI), and informationrelated to an antenna port.

DCI format 2_0 is used to notify the slot format of one or multipleslots. The slot format is defined as one in which each OFDM symbol inthe slot is classified as downlink, flexible, or uplink. For example, ina case that the slot format is 28, DDDDDDDDDDDDXU is applied to 14symbols of OFDM symbols in the slot in which slot format 28 isindicated. Here, D is a downlink symbol, X is a flexible symbol, and Uis an uplink symbol. Note that the slot will be described below.

DCI format 2_1 is used to notify the terminal apparatus 1 of physicalresource blocks and OFDM symbols which may be assumed to be withouttransmission. Note that this information may be referred to as apreemption indication (intermittent transmission indication).

DCI format 2_2 is used for transmission of the PUSCH and Transmit PowerControl (TPC) commands for the PUSCH.

DCI format 2_3 is used to transmit a group of TPC commands for soundingreference signal (SRS) transmission by one or multiple terminalapparatuses 1. An SRS request may be transmitted together with the TPCcommands. An SRS request and TPC commands may be defined in DCI format23 for uplink with no PUSCH and PUCCH or uplink in which the transmitpower control of the SRS is not associated with the transmit powercontrol of the PUSCH.

The DCI for the downlink is also referred to as downlink grant ordownlink assignment. Here, the DCI for the uplink is also referred to asuplink grant or uplink assignment.

The PUSCH is used to transmit Uplink Control Information (UCI) in uplinkradio communication (radio communication from the terminal apparatus 1to the base station apparatus 3). Here, the uplink control informationmay include Channel State Information (CSI) used to indicate a downlinkchannel state. The uplink control information may include SchedulingRequest (SR) used to request an UL-SCH resource. The uplink controlinformation may include a Hybrid Automatic Repeat requestACKnowledgement (HARQ-ACK). The HARQ-ACK may indicate a HARQ-ACK fordownlink data (Transport block, Medium Access Control Protocol Data Unit(MAC PDU), or Downlink-Shared CHannel (DL-SCH)).

The PDSCH is used to transmit downlink data (Downlink Shared CHannel(DL-SCH)) from the Medium Access Control (MAC) layer. In a case of thedownlink, the PSCH is used to transmit System Information (SI), a RandomAccess Response (RAR), and the like.

The PUSCH may be used to transmit the uplink data (Uplink Shared CHannel(UL-SCH)) from the MAC layer or HARQ-ACK and/or CSI with the uplinkdata. The PSCH may be used to transmit the CSI only or the HARQ-ACK andCSI only. In other words, the PSCH may be used to transmit the UCI only.

Here, the base station apparatus 3 and the terminal apparatus 1 exchange(transmit and/or receive) signals with each other in higher layers. Forexample, the base station apparatus 3 and the terminal apparatus 1 maytransmit and/or receive Radio Resource Control (RRC)) signaling (alsoreferred to as a Radio Resource Control (RRC) message or Radio ResourceControl (RRC) information) in an RRC layer. The base station apparatus 3and the terminal apparatus 1 may transmit and/or receive a Medium AccessControl (MAC) control element in a Medium Access Control (MAC) layer.Here, the RRC signaling and/or the MAC control element is also referredto as higher layer signaling. Since the higher layer here refers to ahigher layer viewed from the physical layer, the higher layer mayinclude one or multiple of a MAC layer, an RRC layer, an RLC layer, aPDCP layer, a Non Access Stratum (NAS) layer, or the like. For example,in a processing of the MAC layer, the higher layer may include one ormultiple of an RRC layer, an RLC layer, a PDCP layer, a NAS layer, orthe like.

The PDSCH and PUSCH may be used to transmit the RRC signaling and theMAC control element. Here, in the PDSCH, the RRC signaling transmittedfrom the base station apparatus 3 may be signaling common to multipleterminal apparatuses 1 in a cell. The RRC signaling transmitted from thebase station apparatus 3 may be signaling dedicated to a certainterminal apparatus 1 (also referred to as dedicated signaling). In otherwords, terminal apparatus-specific (UE-specific) information may betransmitted through signaling dedicated to the certain terminalapparatus 1. The PUSCH may be used to transmit UE Capabilities in theuplink.

In FIG. 1, the following downlink physical signals are used for downlinkradio communication. Here, the downlink physical signals are not used totransmit information output from the higher layers but are used by thephysical layer.

-   -   Synchronization signal (SS)    -   Reference Signal (RS)

The synchronization signal may include a Primary Synchronization Signal(PSS) and a Secondary Synchronization Signal (SSS). A cell ID may bedetected by using the PSS and SSS.

The synchronization signal is used for the terminal apparatus 1 toestablish synchronization in a frequency domain and a. time domain inthe downlink. Here, the synchronization signal may be used for theterminal apparatus 1 to select precoding or a beam in precoding orbeamforming performed by the base station apparatus 3. Note that thebeam may be referred to as a transmission or reception filterconfiguration.

A reference signal is used for the terminal apparatus 1 to performchannel compensation on a physical channel. Here, the reference signalis used for the terminal apparatus 1 to calculate the downlink CSI. Thereference signal may be used for a numerology such as a radio parameteror subcarrier spacing, or used for fine synchronization that allows FFTwindow synchronization to be achieved.

According to the present embodiment, at least one of the followingdownlink reference signals are used.

-   -   Demodulation Reference Signal (DMRS)    -   Channel State Information Reference Signal (CSI-RS)    -   Phrase Tracking Reference Signal (PTRS)    -   Tracking Reference Signal (TRS)

The DMRS is used to demodulate a modulated signal. Note that two typesof reference signals may be defined as the DMRS: a reference signal fordemodulating the PBCH and a reference signal for demodulating the PDSCH,or that both reference signals may be referred to as the DMRS. TheCSI-RS is used for measurement of Channel State Information (CSI) andbeam management. The PTRS is used to track the phase in the time axis toensure frequency offset due to phase noise. The TRS is used to ensureDoppler shift during fast travel. Note that the TRS may be used as oneconfiguration of the CSI-RS. For example, a radio resource may beconfigured with one port of a CSI-RS as a TRS.

According to the present embodiment, any one or multiple of thefollowing uplink reference signals are used.

-   -   Demodulation Reference Signal (DMRS)    -   Phrase Tracking Reference Signal (PTRS)    -   Sounding Reference Signal (SRS)

The DMRS is used to demodulate a modulated signal. Note that two typesof reference signals may be defined as the DMRS: a reference signal fordemodulating the PUCCH and a reference signal for demodulating thePUSCH, or that both reference signals may be referred to as the DMRS.The SRS is used for measurement of uplink channel state information(CSI), channel sounding, and beam management. The PTRS is used to trackthe phase in the time axis to ensure frequency offset due to phasenoise.

The downlink physical channels and/or the downlink physical signals arecollectively referred to as a downlink signal. The uplink physicalchannels and/or the uplink physical signals are collectively referred toas an uplink signal. The downlink physical channels and/or the uplinkphysical channels are collectively referred to as a physical channel.The downlink physical signals and/or the uplink physical signals arecollectively referred to as a physical signal.

The BCH, the UL-SCH, and the DL-SCH are transport channels. A channelused in the Medium Access Control (MAC) layer is referred to as atransport channel. A unit of the transport channel used in the MAC layeris also referred to as a Transport Block (TB) and/or a MAC Protocol DataUnit (PDU). A Hybrid Automatic Repeat reQuest (HARQ) is controlled foreach transport block in the MAC layer. The transport block is a unit ofdata that the MAC layer delivers to the physical layer, In the physicallayer, the transport block is mapped to a codeword, and codingprocessing is performed for each codeword.

The reference signal may also be used for Radio Resource Measurement(RRM). The reference signal may also be used for beam management.

Beam management may be a procedure of the base station apparatus 3and/or the terminal apparatus 1 for matching directivity of an analogand/or digital beam in a transmission apparatus (the base stationapparatus 3 in the downlink and the terminal apparatus 1 in the uplink)with directivity of an analog and/or digital beam in a receptionapparatus (the terminal apparatus 1 in the downlink and the base stationapparatus 3 in the uplink) to acquire a beam gain.

Note that the procedure described below may be included as a procedurefor constituting, configuring, or establishing a beam pair link,

-   -   Beam selection    -   Beam refinement    -   Bearn recovery

For example, the beam selection may be a procedure for selecting a beamin communication between the base station apparatus 3 and the terminalapparatus 1. The beam refinement may be a procedure for selecting a beamhaving a higher gain or changing a beam to an optimum beam between thebase station apparatus 3 and the terminal apparatus 1 according to themovement of the terminal apparatus 1. The beam recovery may be aprocedure for re-selecting the beam in a case that the quality of acommunication link is degraded due to blockage caused by a blockingobject, a passing human being, or the like in communication between thebase station apparatus 3 and the terminal apparatus 1.

The beam management may include the beam selection or the beamrefinement. The beam recovery may include the following procedures.

-   -   Detection of beam failure    -   Discovery of new beam    -   Transmission of beam recovery request    -   Monitor of response to beam recovery request

For example, the Reference Signal Received Power (RSRP) of the SSSincluded in the CSI-RS or the SS/PBCH block may be used, or the CSI maybe used, in selecting the transmit beam of the base station apparatus 3in the terminal apparatus 1. The CSI-RS Resource Index (CRI) may beused, or an index indicated in the sequence of the demodulationreference signal (DMRS) used for demodulation of the PBCH and/or PBCHincluded in the SS/PBCH block may be used, as a report to the basestation apparatus 3.

The base station apparatus 3 indicates the CRI or the time index of theSS/PBCH in indicating the beam to the terminal apparatus 1, and theterminal apparatus 1 receives based on the indicated CRI or the timeindex of the SS/PBCH. At this time, the terminal apparatus 1 mayconfigure a spatial filter, based on the indicated CR1 or the time indexof the SS/PBCH for reception. The terminal apparatus 1 may receive byusing the assumption of Quasi-Co-Location (QCL). One signal (antennaport, synchronization signal, reference signal, or the like) being inQCL or being assumed to be in QCL with another signal (antenna port,synchronization signal, reference signal, or the like) can beinterpreted as one signal being associated with another signal.

In a case that a Long Term Property of a channel on which one symbol inone antenna port is carried may he estimated from a channel on which onesymbol in the other antenna port is carried, the two antenna ports aresaid to be in QCL. The Long Term Property of the channel includes atleast one of a delay spread, a Doppler spread, a Doppler shift, anaverage gain, or an average delay. For example, in a case that anantenna port 1 and an antenna port 2 are in QCL with respect to theaverage delay, this means that a reception timing for the antenna port 2may be estimated from a reception timing for the antenna port 1.

The QCL may also be expanded to beam management. For this purpose,spatially expanded QCL may be newly defined. For example, the Long TermProperty of a channel in spatial QCL assumption may be an Angle ofArrival ((AoA), a Zenith angle of Arrival (ZoA), or the like) and/or anAngle Spread (for example, Angle Spread of Arrival (ASA) or a Zenithangle Spread of Arrival (ZSA)), a transmission angle (AoD, ZoD, or thelike) or an Angle Spread of the transmission angle (for example, anAngle Spread of Departure (ASD) or a Zenith angle Spread of Departure(ZSS)), Spatial Correlation, or a reception spatial parameter, in aradio link or channel.

For example, in a case that an antenna port 1 and an antenna port 2 areconsidered to be QCL, with respect to the reception spatial parameters,it means that the receive beam (reception spatial filter) for receivinga signal from the antenna port 2 can be inferred from the receive beamfor receiving a signal from the antenna port 1.

Combinations of long terms properties which may be considered to be QCLmay be defined as QCL types. For example, the following types may bedefined.

-   -   Type A: Doppler shift, Doppler spread, average delay, delay        spread    -   Type B: Doppler shift, Doppler spread    -   Type C: Average delay, Doppler shift    -   Type D: Reception spatial parameters

The above-described. QCL types may configure and/or indicate the QCLassumption of one or two reference signals and the PDCCH or the PDSCHDMRS in the RRC and/or MAC layer and/or DCI as a TransmissionConfiguration Indication (TCI). For example, in a case that index #2 ofthe PBCHISS block and the QCL type A+the QCL type B are configuredand/or indicated as one state of the TCI at a time when the terminalapparatus 1 receives the PDCCH, the terminal apparatus 1 may consider,at a time when receiving the PDCCH DMRS, the Doppler shift, the Dopplerspread, the average delay, the delay spread, and the reception spatialparameters in the reception of the PBCH/SS block index #2 as the longterm properties of the channel to receive the DMRS of the PDCCH toperform synchronization or channel estimation. At this time, thereference signal indicated by the TCI (the PBCH/SS block in the exampledescribed above) may be referred to as a source reference signal, and areference signal affected by the long term properties inferred from thelong terns properties of the channel at a time when the source referencesignal (the PDCCH DMRS in the example described above) is received maybe referred to as a target reference signal. The TCI may be configuredwith multiple TCI states and a combination of a source reference signaland a QCL type for each state in the RRC, and indicated to the terminalapparatus 1 by the MAC layer or the DCI.

According to this method, operation of the base station apparatus 3 andthe terminal apparatus 1 equivalent to beam management may be defined asbeam management and beam indication/report, based on the spatial QCLassumption and radio resources (time and/or frequency).

The subframe will now be described. The subframe in the presentembodiment may also be referred to as a resource unit, a radio frame, atime period, or a time interval

FIG. 2 is a diagram illustrating a schematic configuration of a downlinkslot according to a first embodiment of the present invention. Each ofthe radio frames is 10 ms in length. Each of the radio frames includes10 subfraines and W slots. One slot includes X OFDM symbols. In otherwords, the length of one subframe is 1 ms. For each of the slots, timelength is defined based on subcarrier spacings. For example, in a casethat the subcarrier spacing of an OFDM symbol is 15 kHz and NormalCyclic Prefixes (NCPs) are used, X=7 or X=14, and X=7 ad X=14 correspondto 0.5 ms and 1 ms, respectively. In a case that the subcarrier spacingis 60 kHz, X=7 or X=14, and X=7 and X=14 correspond to 0.125 ms and 0.25ms, respectively. For example, in a case of X=14, W=10 is used in a casethat the subcarrier spacing is 15 kHz, and W=40 is used in a case thatthe subcarrier spacing is 60 kHz. FIG. 2 illustrates a case of X=7 as anexample. Note that a case of X=14 can be similarly configured byexpanding the case of X=7. The uplink slot is defined similarly, and thedownlink slot and the uplink slot may be defined separately. Thebandwidth of the cell of FIG. 2 may also be defined as a BandWidth Part(BWP). The slot may also be defined as a Transmission Time Interval(TTI). A slot may not be defined as TTI. TTI may be a transmissionperiod of a transport block.

The signal or the physical channel transmitted in each of the slots maybe represented by a resource grid. The resource grid is defined bymultiple subcarriers and multiple OFDM symbols. The number ofsubcarriers constituting one slot depends on each of the downlink anduplink bandwidths of a cell. Each element in the resource grid isreferred to as a resource element. The resource element may beidentified. by using a subcarrier number and an OFDM symbol number.

A resource grid is used to represent mapping of a certain physicaldownlink channel (such as the PDSCH) or a certain physical uplinkchannel (such as the PUSCH) to resource elements. For example, in a casethat the subcarrier spacing is 15 kHz, and in a case that the number Xof OFDM symbols included in the subframe is 14 and NCPs are used, onephysical resource block is defined by 14 continuous OFDM symbols in thetime domain and by 12* Nmax continuous subcarriers in the frequencydomain. Nmax is the maximum number of resource blocks determined by thesubcarrier spacing configuration μ described below. In other words, theresource grid includes (14*12*Nmax, μ) resource elements. In a case ofExtended CPs (ECPs), since it is supported only with the subcarrierspacing of 60 kHz, one physical resource block is defined by, forexample, 12 (the number of OFDM symbols included in one slot)*4 (thenumber of slots included in one subframe)=48 continuous OFDM symbols inthe time domain and by 12*Nmax, μ continuous subcarriers in thefrequency domain. In other words, the resource grid includes(48*12*Nmax, μ) resource elements.

As a resource block, a reference resource block, a common resourceblock, a physical resource block, a virtual resource block is defined.One resource block is defined as 12 subcarriers that are continuous inthe frequency domain. Reference resource blocks are common in allsubcarriers, and, for example, may be configured with resource blocks atsubcarrier spacing of 15 kHz, and may be numbered in ascending order.Subcarrier index 0 at reference resource block index 0 may be referredto as a reference point A (which may simply be referred to as a“reference point”), The common resource blocks are resource blocksnumbered from 0 in ascending order in each subcarrier spacingconfiguration μ from the reference point A. The resource grid describedabove is defined by these common resource blocks. Physical resourceblocks are resource blocks numbered in ascending order from 0 includedin a bandwidth part (BWP) described below, and the physical resourceblocks are resource blocks numbered in ascending order from 0 includedin the bandwidth part (BWP). A certain physical uplink channel is firstmapped to a virtual resource block. Thereafter, the virtual resourceblock is mapped to a physical resource block. (from TS38.211)

Next, the subcarrier spacing configuration μ will be described. Asdescribed above, multiple OFDM numerologies are supported in NR. In theBWP, the subcarrier spacing configuration μ (μ=0,1, . . . , 5) and thecyclic prefix length are given by a higher layer for the downlink BAP,and are given by a higher layer in the uplink BWP. Here, in a case thatμ is given, the subcarrier spacing Δf is given by Δf=2{circumflex over( )}μ*15 (kHz).

In the subcarrier spacing configuration μ, the slots are counted inascending order from 0 to N{circumflex over ( )}{subframe} . . .{slot}−1 in the subframe, and counted in ascending order from 0 toN{circumflex over ( )}{frame, μ}_{slot}−1 in the frame. N{circumflexover ( )}{slot}_{symb} continuous OFDM symbols are in the slot, based onthe slot configuration and the cyclic prefix. N{circumflex over( )}{slot}_{symb} is 14. The start of the slot n{circumflex over( )}{μ}_{s} in the subframe is aligned with the start in time of then{circumflex over ( )}{μ}_{s} N{circumflex over ( )}{slot}_{symb}-thOFDM symbol in the same subframe.

The subframe, the slot, and a mini-slot will now be described. FIG. 3 isa diagram illustrating the relationship between the subframe and theslot and the mini-slot in the time domain. As illustrated in FIG. 3,three types of time units are defined. The subframe is 1 ms regardlessof the subcarrier spacing. The number of OFDM symbols included in theslot is 7 or 14, and the slot length depends on the subcarrier spacing.Here, in a case that the subcarrier spacing is 15 kHz, 14 OFDM symbolsare included in one subframe. A downlink slot may be referred to asPDSCH mapping type A. An uplink slot may be referred to as PUSCH mappingtype A.

The mini-slot (which may be referred to as a sub-slot) is a time unitincluding OFDM symbols that are less in number than the OFDM symbolsincluded in the slot. FIG. 3 illustrates, by way of example, a case thatthe mini-slot includes 2 OFDM symbols. The OFDM symbols in the mini-slotmay match the timing for the OFDM symbols constituting the slot. Notethat the smallest unit of scheduling may be a slot or a mini-slot.Allocating a mini-slot may be referred to as non-slot based scheduling.Scheduling the mini-slots may be expressed as scheduling resources inwhich the relative time positions of the starting positions of thereference signal and the data are fixed. A downlink mini-slot may bereferred to as PDSCH mapping type B. An uplink mini-slot may be referredto as PUSCH mapping type B.

FIG. 4 is a diagram illustrating an example of a slot format. Here, acase that the slot length is 1 ms at a subcarrier spacing of 15 kHz isillustrated as an example. In FIG. 4, D represents the downlink, and Urepresents the uplink. As illustrated in FIG. 4, during a certain timeinterval (for example, the minimum time interval to be allocated to oneUE in the system), the subframe may include at least one of thefollowings:

-   -   downlink symbol,    -   flexible symbol, or    -   uplink symbol.

Note that these ratios may be predetermined as slot formats. Theseratios may also be defined by the number of downlink OFDM symbolsincluded in the slot or the start position and the end position withinthe slot. These ratios may also be defined by the number of uplink OFDMsymbols or DFT-S-OFDM symbols included in the slot or the start positionand the end position within the slot. Note that scheduling the slots maybe expressed as scheduling resources in which the relative timepositions of the reference signal and the slot boundary are fixed.

The terminal apparatus 1 may receive a downlink signal or a downlinkchannel in a downlink symbol or a flexible symbol. The terminalapparatus 1 may transmit an uplink signal or a downlink channel in anuplink symbol or a flexible symbol.

FIG. 4(a) is an example in which the entire subframe is used fordownlink transmission during a certain time interval (which may bereferred to as, for example, a minimum unit of a time resource that canhe allocated to one UE, or a time unit, or multiple minimum units oftime resources may be collectively referred to as a time unit). In FIG.4(b), an uplink is scheduled via the PDCCH for example by using thefirst time resource, and an uplink signal is transmitted after a gap fora processing delay of the PDCCH, a time for switching from the downlinkto the uplink, and a flexible symbol including generation of a transmitsignal. In FIG. 4(c), the PDCCH and/or downlink PDSCH are transmitted byusing the first time resource, and the PUSCH or PUCCH are transmittedafter a gap for a processing delay, a time for switching from thedownlink to the uplink, and generation of a transmit signal. Here, forexample, the uplink signal may be used to transmit the HARQ-ACK and/orCSI, namely, the UCI. In FIG. 4(d), the PDCCH and/or PDSCH aretransmitted by using the first time resource, and the uplink PUSCHand/or PUCCH are transmitted after a gap for a processing delay, a timefor switching from the downlink to the uplink, and generation of atransmit signal. Here, for example, the uplink signal may be used totransmit the uplink data, namely, the UL-SCH. FIG. 4(e) is an example inwhich the entire subframe is used for uplink transmission (PUSCH orPUCCH).

The above-described downlink part and uplink part ay include multipleOFDM symbols as is the case with LTE.

FIG. 5 is a diagram illustrating an example of beamforming. Multipleantenna elements are connected to one Transceiver unit (TXRU) 10. Thephase is controlled by using a phase shifter 11 for each antenna elementand a transmission is performed from an antenna element 12, thusallowing a beam for a transmit signal to be directed in any direction.Typically, the TXRU may be defined as an antenna port, and only theantenna port may be defined for the terminal apparatus 1. Controllingthe phase shifter 11 allows setting of directivity in any direction.Thus, the base station apparatus 3 can communicate with the terminalapparatus 1 by using a high gain beam.

Hereinafter, the bandwidth part (BWP) will be described. The BWP is alsoreferred to as a carrier BWP. The BWP may he configured for each of thedownlink and the uplink. The BWP is defined as a set of continuousphysical resources selected from continuous subsets of common resourceblocks. The terminal apparatus 1 may be configured with up to four BWPsin which one downlink carrier BWP is activated at a certain time. Theterminal apparatus 1 may be configured with up to four BWPs in which oneuplink carrier BWP is activated at a certain time. In the case ofcarrier aggregation, the BWP may be configured for each serving cell. Atthis time, configuring one BWP in a certain serving cell may heexpressed as configuring no BWP. Configuring two or more BWPs may beexpressed as configuring BWP.

In an activated serving cell, there is always one active (activated)BWP. BWP switching for a certain serving cell is used to activate artinactive (deactivated) BWP and deactivate an active (activated) BWP. BWPswitching for a certain serving cell is controlled by the PDCCHindicating a downlink assignment or an uplink grant, in addition of theSpCell (PCell or PSCell) or the activation of the SCell, one BWP isinitially active without receiving the PDCCH indicating a downlinkassignment or an uplink grant. The initially active BWP may be specifiedby an RRC message transmitted from the base station apparatus 3 to theterminal apparatus 1. The active BWP for a certain serving cell isspecified by the RRC or the PDCCH transmitted from the base stationapparatus 3 to the terminal apparatus 1. In Unpaired spectrum (such asTDD bands), the DL BWP and the UL BWP are paired, and BWP switching iscommon to the UL and the DL. In the active BWP for each of the activatedserving cells for which the BWP is configured, the MAC entity of theterminal apparatus 1 applies normal processing. The normal processingincludes transmitting the UL-SCH, transmitting the RACH, monitoring thePDCCH, transmitting the PUCCH, and receiving the DL-SCH. In an inactiveBWP for each of the activated serving cells for which the BWP isconfigured, the MAC entity of the terminal apparatus 1 does not transmitthe UL-SCH, does not transmit the RACH, does not monitor the PDCCH, doesnot transmit the PUCCH, and does not receive the DL-SCH. In a case thata certain serving cell is deactivated, an active BWP may not be present(for example, the active BWP is deactivated).

The terminal apparatus 1 may be configured with one primary cell and upto 15 secondary cells.

The time and frequency resources for reporting the CSI used by theterminal apparatus 1 are controlled by the base station apparatus 3. TheCSI includes a Channel Quality Indicator (CQI), a Precoding MatrixIndicator (PMI), a CSI-RS Resource Indicator (CRI), a Strongest LayerIndication (SLI), a rank indication (RI), and/or a Layer-1 ReferenceSignal Received Power (L1-RSRP). For the CQI, PMI, CRI, SLI, RI, andL1-RSRP, the terminal apparatus 1 is configured by a higher layer with aconfiguration related to N (N is equal to or greater than 1) CSIreports, a configuration related to resources of M (M is equal to orgreater than 1) CSI reference signals (CSI RSs), and a configurationrelated to one CSI measurement including L (L is equal to or greaterthan 1) links. The configuration related to the CSI measurement includesa list of configurations related to the CSI reports, a list ofconfigurations related to the CSI resources, a list of configurations ofthe links, and a list of trigger states. Each will be described below.

Each of the configurations related to the CSI reports is associated withone downlink BWP (the BWP identity of a higher layer), and each of theconfigurations related to the CSI reports includes the followingparameters to be reported.

-   -   One identity for identifying a configuration related to the CSI        report    -   Operation in the time domain (for example, periodic,        semi-persistent, or Aperiodic)    -   CSI parameters to be reported (for example, CRI, RI, PMI, CQI,        or the like)    -   Configuration in the frequency domain (including each of the        information to configure the broadband CQI or the subband CQI,        and information to configure the wideband PMI or the subband        PMI)    -   Configuration of restriction on CSI measurement (measurement        restriction configuration, which may be configured for each of        the channel measurement and interference measurement)    -   Codebook configuration (information of the CSI type (information        for indicating type 1 or type 2) and codebook subset        restriction)    -   Maximum number of CQI per report (which may be information for        indicating either one codeword or two codewords)    -   Assumption of the CQI table table including up to 64 QAM, CQI        table including up to 256 QAM, URLLC, or the like)

Each of the configurations related to the CSI resources includesinformation related to S (S is equal to or greater than 1) CSI-RSresource sets, and each CSI-RS resource set includes multiple CSI-RSresources (a NZPCSI-RS for channel measurement or interferencemeasurement, and a CSI-Interference Measurement (IM) resource forinterference measurement), and a configuration related to resources ofthe SS/PBCH block used for L1-RSRP calculation. Here, the NZP CSI-RSresource is a CSI-RS in which the sequence is generated in accordancewith a generation method defined in advance in the specification, andthe CSI-RS is mapped to resource elements. Each of the configurationsrelated to the CSI resources is placed in an identified BWP in a higherlayer, and the configurations related to all the CSI resources linked toa configuration related to one CSI report is the same BWP.

Next, the channel measurement and interference measurement describedabove will be described. The channel measurement is to measure theamount related to the quality of each layer or each codeword in a casethat the downlink desired signal or channel or spatial multiplexing isassumed for the CSI measurement, and the interference measurement is tomeasure the amount of interference in each layer or codeword in a casethat the downlink interference signal or channel or spatial multiplexingis assumed for the CSI measurement. Here, “layer” refers to the numberof PDSCHs to be spatially multiplexed.

Note that the configuration (ssb-Resources) related to the resources ofthe SS/PBCH block used for the L1-RSRP calculation may be included ineach of the configurations related to the CSI resources.

The operation in the time domain of the CSI-RS resources may be includedin each of the configurations related to the CSI resources. Theoperation in the time domain of the CSI-RS resources may be included ineach of the configurations related to CSI-RS resource sets.

The configuration of each link includes an indication of theconfiguration related to the CSI report, an indication of the CSIconfiguration, and an indication of whether to measure the channelmeasurement or the interference measurement. The configuration of eachlink may include multiple trigger states for dynamically selecting aconfiguration related to the CSI report for one or multiple aperiodicCSI reports.

Each trigger state is associated with a configuration related to one ormultiple CSI reports, and the configuration related to each CSI reportis linked to a configuration related to one or multiple periodic,semi-persistent, or aperiodic CSI reference signals. Here, the terminalapparatus may assume the following, depending on the number ofconfigurations associated with the linked CSI resources.

-   -   In a case that one configuration related to CSI resources is        configured, the resource configuration is for channel        measurement for L1-RSRP calculation.    -   In a case that two configurations related to CSI resources are        configured, the first configuration related to CSI resources is        for channel measurement, and the second configuration related to        CSI resources is for interference measurement on the CSI-IM or        the NZP CSI-RS resource.    -   In a case that three configurations related to CSI resources are        configured, the first configuration related to CSI resources is        for channel measurement, the second configuration related to CSI        resources is for interference measurement on the CSI-IM        resource, and the third configuration related to CSI resources        is for interference measurement on the NZP CSI-RS resource.

For the CSI measurement, the terminal apparatus 1 may assume thefollowing.

-   -   Each NZP CSI-RS port configured for the interference measurement        corresponds to transmission layers of interference;    -   All transmission layers of interference on the NZP CSI-RS port        is considered for the associated Energy per resource element        (EPRE); and    -   There are other interference signals on the NZP CSI-RS resource        for the channel measurement, the CSI-RS resource for the        interference measurement, or the CSI-IM resource for        interference measurement

Here, EPRE represents the energy of the NZP CSI-RS per resource element.Specifically, the base station apparatus 3 is configured with each ofthe ratio (Pc) of the PDSCH EPRE to the EPRE of the NZP CSI-RS, theratio (Pc-PDCCH) of the PDCCH EPRE to the EPRE of the NZP CSI-RS, andthe ratio (Pc_SS) of the EPRE of the SS/PBCH block to the EPRE of theNZP CSI-RS. In this way, the EPRE can be considered for the CSImeasurement from the ratio of the energy in which the CSI-RS EPRE isconfigured.

A configuration related to one or multiple CSI reports for the channelmeasurement and/or the interference measurement on one or multiplecomponent carriers and/or trigger states for one or multiple CSI-RSresource sets are configured by a higher layer for a CSI-RS resource setin which the operation in the time domain of the CSI-RS resource set isaperiodic. For a trigger of an aperiodic CSI report, one set of CSItrigger states is configured with higher layer parameters, and the CSItrigger states are associated with any one candidate of DL MVP. Theterminal apparatus 1 does not expect that the CSI report for thedownlink BWP not activated is triggered. Each trigger state is initiatedby using a CSI request field included in the DCI (for example, DCIformat 0_1).

In this case, the terminal apparatus performs the following operations.

-   -   In a case that the value of the CSI request field is 0, CSI is        not requested    -   In a case that the number of CSI trigger states is greater than        2^(NTS)−1, the terminal apparatus 1 receives, from the MAC        layer, a selection command to be used for mapping to the        2^(NTS)−1 trigger states to the code point of the CSI request        field. Here, N_(TS) is the bit size of the CSI request field        configured in a higher layer. N_(TS) may be configured with any        value from {0, 1, 2, 3, 5, 6}.    -   In a case that the number of CSI trigger states is smaller than        or equal to 2^(NTS)−1, the CSI request field directly indicates        the trigger state and the QCL assumption of the terminal        apparatus 1.    -   For the aperiodic CSI-RS resource associated with each CSI        trigger state, the terminal apparatus 1 is indicated a source        reference signal of QCL and the QCL configuration of the QCL        type from the higher layer (for example, the TCI may he used).

Here, N_(TS) is the number of bits of the CSI request field of the DCI,and the number of states of the triggers (N_(CSI)) for the aperiodic CSIreport configured by the RRC may be greater than or smaller than orequal to 2^(NTS)−1.

In a case that a configuration related to a CSI resource linked to aconfiguration related to one CSI report has a configuration related tomultiple aperiodic CSI-RS resource sets, and a portion of the aperiodicCSI-RS resource sets is associated with a trigger state, a bitmap isconfigured by a higher layer for selecting a CSI-IM resource or a NZPCSI-RS resource set per trigger state for each CSI-RS resource set.

The configuration described above will be described, Information relatedto the CSI measurement may be included in information (for example,ServingCellConfigDedicated) configured for the terminal apparatus 1 foreach cell. In other words, the information related to the CSImeasurement is configured for each cell, and the information related tothe CSI measurement of each cell includes the following information.

-   -   List of configurations related to N CSI reports    -   List of configurations related to M CSI reference signals    -   List of links between configurations related to L CSI reports        and configurations for related to CSI reference signals        (csi-MeasIdToAddModList)    -   Information related to triggers of CSI reports (the number of        bits N_(TS) of the CSI request field and/or the trigger state        corresponding to the value of the CSI request field)

The configuration related to each CSI report includes the index or theidentity of the configuration related to the CSI report, information forconfiguring the operation in the time domain, and information forconfiguring which CSI to report. The configuration related to each CSIreport may also include a BWP index for identifying one BWP.

In a case that the information for configuring the operation in the timedomain indicates periodic or semi-persistent, a period (number of slots)for reporting CSI may he included. In a case that the information forconfiguring the operation in the time domain indicates Aperiodic, theinformation related to the offset of the number of slots from the slotwhere the aperiodic CSI report is triggered to transmitting the CSIreport, In a case that the information for configuring the operation inthe time domain indicates Aperiodic, the configuration related to eachCSI report may include the index of the trigger state of the CSI report.

The configuration related to each link may include the index or theidentity of the configuration related to the CSI report to be linked,the index or the identity of the configuration related to the CSIreference signal, and the identity of the link.

FIG, 6 illustrates an example of an RRC configuration related to the CSImeasurement and a CSI request field in a certain serving cell c. Here,the description is made as the number of trigger states configured bythe RRC N_(CSI)=3, the number of bits of the CSI request field N_(TS)=2.Note that here, it is assumed that the number of BWPs configured for theserving cell is 2. As illustrated in FIG. 6, a list of configurationsfor CSI reports is configured for the information related to the CSImeasurement of the serving cell c, and four configurations related tothe CSI reports are configured in the list. Among them, theconfigurations of aperiodic CSI reports are configurations #1 to #3related to the CSI report.

The configuration #1 related to the CSI report is associated with thetrigger state #0, the configuration #2 related to the CSI report isassociated with the trigger state #1, and the configuration #3 relatedto the CSI report is associated with the trigger state #2. In this case,because of N_(CSI)=2^(NTS)−1, it is mapped directly to the 2-bit CSIrequest field included in the DCI format. As illustrated in FIG. 6, “00”of the CSI request field does not transmit the CSI report. The triggerstate #0 is associated with “01”, the trigger state #1 is associatedwith “10”, and the trigger state #2 is associated with “11”.

The terminal apparatus 1 reports the CSI in the PUSCH, based on theconfiguration related to the CSI report configured by the RRC and theconfiguration related to the CSI report associated with the value of theCSI request field included in the DCI. At this time, the terminalapparatus 1 measures the CSI, based on the CSI parameters to be reportedincluded in the configuration related to the CSI report, from the CSI-RSresource set or the CSI-RS resource for measuring the CSI from theconfiguration related to the CSI resource associated with theconfiguration related to the CSI report.

The configuration related to each CSI report is associated with the BWPin the serving cell. In FIG. 6, the trigger state #1 and the triggerstate #2 are associated with the BWP index #0 and the BWP index #1,respectively. In other words, in a case that 10 is indicated as thevalue of the CSI request field, the terminal apparatus 1 reports the CSIin the BWP #1. In other words, the value (information) of the CSIrequest field indicates one of multiple trigger states, each of themultiple trigger states is configured for each serving cell, and isassociated with a configuration related to one or multiple CSI reportsand a configuration related to one or multiple reference signals for theCSI measurement. Note that the value of the CSI request field may bestated as information included in the CSI request field.

Here, “active” is configured as the BWP index of the trigger state #0rather than the actual index of the configured BWP. This means beingassociated with the activated BWP. For example, in a case that the BWPindicating khe BWP index #0 is activated in a certain slot for theterminal apparatus 1, the CSI request field “01” measures the CSI in theBWP corresponding to the activated BWP index #0, and reports the CS!. Onthe other hand, in a case that the BWP corresponding to the BWP index #1is activated in a certain slot, the CSI request field “01” measures theCSI in the BWP corresponding to the activated BWP index #1, and reportsthe CSI. In other words, the CSI request field included in the DCI ofthe PDCCH includes a trigger state, each trigger state is associatedwith a configuration related to one or multiple CSI reports and aconfiguration related to one or multiple CSI resources, and one of themultiple trigger skates is configured to be associated with theactivated BWP of the serving cell c.

FIG. 7 illustrates an example of a configuration and a CSI request fieldin a case of the number of trigger states configured by the RRCN_(CSI)=4, and the number of bits of the CSI request field N_(TS)=2 in acertain serving cell. in the example of FIG. 7, as in FIG, 6, each ofthe configurations related to the CSI report in which the time operationis aperiodic is associated with a BWP index and a trigger state.

In the example of FIG. 7, because of N_(CSI)>2^(NTS)−1, the triggerstates for each code point “01”, “10”, and “11” in the CSI request fieldis selected via the MAC layer. As illustrated in FIG. 7, one or multipletrigger states may be selected for the four trigger states configured bythe RRC by using a bitmap for indicating each trigger state for eachcode point, In the example of FIG. 7, a 4-bit bitmap “1000” forselection of each trigger state for the code point “01” is indicated tothe terminal apparatus 1 and mapped to correspond to the CSI requestfield “01”. This means that the trigger state #0 is configured to thecode point “01” of the CSI request field. In this manner, each codepoint is selected by a bitmap corresponding to each trigger state in theMAC layer. In other words, the CSI request field included in the DCI ofthe PDCCH includes a trigger state, and each trigger state is associatedwith a configuration related to one or multiple CSI reports and aconfiguration related to one or multiple CSI resources, One or multipletrigger states associated with the CSI request field are selected fromthe multiple trigger states by using a bitmap in the MAC layer, and aremapped to each of the code points in the CSI request field.

FIG. 8 illustrates an example in a case that two serving cells areconfigured. Here, an example is illustrated in which two serving cellsare configured as the number of serving cells, and trigger states areallocated to the configurations related to the aperiodic CSI report ineach cell. As illustrated in the drawing, multiple configurationsrelated to CSI reports are associated in the CSI request field. Forexample, the trigger state #1 of the serving cell #1 and the triggerstate #1 of the serving cell #2 are configured to the code point “01”.

Here, in a case that “10” is indicated as the value of the CSI requestfield for the terminal apparatus 1 in a certain slot, the terminalapparatus 1 reports the CSI of the BWP #0 of the serving cell #1 and theCSI of the BWP #0 of the serving cell #2. In this case, in a case thatthe BWP #0 of the serving cell #1 and the BWP #0 of the serving cell #2are activated together, the terminal apparatus 1 reports the CSI of theBWP #0 of the serving cell #1 and the BWP #0 of the serving cell #2.

In a case that the BWP #0 of the serving cell #1 is activated but theBWP #0 of the serving cell #2 is not activated, the terminal apparatus 1reports the CSI of the BWP #0 of the serving cell #1. In this way,multiple serving cells are configured, and the CSI report of eachserving cell indicated by the value of the CSI request field is made. Inother words, the terminal apparatus 1 receives the PDCCH for carryingthe DCI including the CSI request field, and in a case that the CSIreport of the BWP in the multiple serving cells is triggered based onthe CSI request field, the terminal apparatus 1 transmits the CSI reportof only the BWP indicated by the activated BWP index. At this time, theCSI request field indicates a trigger state, and the trigger stateindicates one of multiple states. Each state of the multiple states isconfigured for each serving cell, and is associated with a configurationrelated to one or multiple CSI reports and a configuration related toone or multiple CSI resources and a BWP index for each serving cell.

Here, in the example described above, a configuration related to one CSIreport is configured for one value of the CSI request field, butmultiple CSI reports may be associated.

In the example described above, a case is illustrated that theconfiguration related to the CSI report of each serving cell is alwaysassociated with the configuration related to the BWP index, but in acase that there is one BWP, the associated information may not beconfigured. In this case, the CSI measurement and the CSI reporting maybe performed based on the bandwidth of the serving cell.

Although an example is described above in which the CSI report istransmitted based on whether or not the BWP is activated, even in a casethat the serving cell is deactivated, the CSI report in the serving cellmay not be transmitted, and the CSI of only the activated serving celland/or activated BWP may be reported.

Although, in the example described above, the information for indicatingthe index of the trigger state is included in the configuration relatedto the CSI report, the configuration related to the CSI measurement mayinclude the list of trigger states, and which configuration related tothe CSI report is included in each trigger state may be configured.

In other words, in the present invention, the terminal apparatus 1 mayreport only the CSI of the activated serving cell. The terminalapparatus 1 may report only the CSI of the activated BWP in a case of acell in which the BWP is configured and activated. The terminalapparatus 1 may not report the CSI of the deactivated serving cell. TheCSI of the deactivated BWP may not be reported. The BWP index includedin the configuration related to the CSI report may be configured foreach serving cell, and the serving cell index and the BWP index may beused for identification of the BWP.

An aspect of the present embodiment may be operated in carrieraggregation or dual connectivity with the Radio Access Technologies(RAT) such as LTE and LTE-A/LTE-A Pro. In this case, the aspect may beused for some or all of the cells or cell groups, or the carriers orcarrier groups (for example, Primary Cells (PCells), Secondary Cells(SCells), Primary Secondary Cells (PSCells), Master Cell Groups (MCGs),or Secondary Cell Groups (SCGs)). The aspect may be independentlyoperated and used in a stand-alone manner. In the dual connectivityoperation, the Special Cell (SpCell)) is referred to as a PCell of theMCG or a PSCell of the SCG, respectively, depending on whether the MACentity is associated with the MCG or is associated with the SCG. Exceptthe dual connectivity operation, the Special Cell (SpCell) is referredto as a PCell. The Special Cell (SpCell) supports PUCCH transmission andcontention based random access.

Configurations of apparatuses according to the present embodiment willbe described below. Here, an example of a case is illustrated in whichCP-OFDM is applied as a downlink radio transmission scheme, and CP-OFDMor DFTS-OFDM (SC-FDM) is applied as an uplink radio transmission scheme,

FIG. 9 is a schematic block diagram illustrating a configuration of theterminal apparatus 1 according to the present embodiment. As illustratedin FIG. 9, the terminal apparatus 1 is configured to include a higherlayer processing unit 101, a controller 103, a receiver 105, atransmitter 107, and a transmit and/or receive antenna 109. The higherlayer processing unit 101 includes a radio resource control unit 1011, ascheduling information interpretation unit 1013, and a Channel StateInformation (CSI) report control unit 1015. The receiver 105 includes adecoding unit 1051, a demodulation unit 1053, a demultiplexing unit1055, a radio receiving unit 1057, and a measurement unit 1059. Thetransmitter 107 includes a coding unit 1071, a modulation unit 1073, amultiplexing unit 1075, a radio transmitting unit 1077, and an uplinkreference signal generation unit 1079.

The higher layer processing unit 101 outputs the uplink data (thetransport block) generated by a user operation or the like, to thetransmitter 107. The higher layer processing unit 101 performsprocessing of the Medium Access Control (MAC) layer, the Packet DataConvergence Protocol (PDCP) layer, the Radio Link Control (RLC) layer,and the Radio Resource Control (RRC) layer.

The radio resource control unit 1011 included in the higher layerprocessing unit 101 manages various pieces of configuration informationof the terminal apparatus 1. The radio resource control unit 1011generates information allocated in each channel for uplink, and outputsthe generated information to the transmitter 107.

The scheduling information interpretation unit 1013 included in thehigher layer processing unit 101 interprets the DCI (schedulinginformation) received through the receiver 105, generates controlinformation for control of the receiver 105 and the transmitter 107, inaccordance with a result of interpreting the DCI, and outputs thegenerated control information to the controller 103.

The CSI report control unit 1015 indicates to the measurement unit 1059to derive Channel State Information (RI/PMI/CQI/CRI) relating to the CSIreference resource. The CSI report control unit 1015 indicates to thetransmitter 107 to transmit RI/PMI/CQI/CRI. The CSI report control unit1015 sets a configuration that is used in a case that the measurementunit 1059 calculates CQI.

In accordance with the control information from the higher layerprocessing unit 101, the controller 103 generates a control signal forcontrol of the receiver 105 and the transmitter 107. The controller 103outputs the generated control signal to the receiver 105 and thetransmitter 107 to control the receiver 105 and the transmitter 107.

In accordance with the control signal input from the controller 103, thereceiver 105 demultiplexes, demodulates, and decodes a reception signalreceived from the base station apparatus 3 through the transmit and/orreceive antenna 109, and outputs information resulting from the decodingto the higher layer processing unit 101.

The radio receiving unit 1057 converts (down-converts) a downlink signalreceived through the transmit and/or receive antenna 109 into a signalof an intermediate frequency, removes unnecessary frequency components,controls an amplification level in such a manner as to suitably maintaina signal level, performs orthogonal demodulation based on an in-phasecomponent and an orthogonal component of the received signal, andconverts the resulting orthogonally-demodulated analog signal into adigital signal. The radio receiving unit 1057 removes a portioncorresponding to a Guard. Interval (GI) from the digital signalresulting from the conversion, performs Fast Fourier Transform (FFT) onthe signal from which the Guard Interval has been removed, and extractsa signal in the frequency domain.

The demultiplexing unit 1055 demultiplexes the extracted signal into thedownlink PDCCH, the downlink PDSCH, and the downlink reference signal.The demultiplexing unit 1055 performs channel compensation for the PDCCHand PUSCH, based on the channel estimate value input from themeasurement unit 1059. The demultiplexing unit 1055 outputs the downlinkreference signal resulting from the demultiplexing, to the measurementunit 1059.

The demodulation unit 1053 demodulates the downlink PDCCH and outputs asignal resulting from the demodulation to the decoding unit 1051. Thedecoding unit 1051 attempts to decode the PDCCH, In a case of succeedingin the decoding, the decoding unit 1051 outputs downlink controlinformation resulting from the decoding and an RNTI to which thedownlink control information corresponds, to the higher layer processingunit 101.

The demodulation unit 1053 demodulates the PDSCH in compliance with amodulation scheme notified with the downlink grant, such as QuadraturePhase Shift Keying (QPSK), 16 Quadrature Amplitude Modulation (QAM), 64QAM, or 256 QAM and outputs a signal resulting from the demodulation tothe decoding unit 1051. The decoding unit 1051 performs decoding inaccordance with information of a transmission or an original coding ratenotified with the downlink control information, and outputs, to thehigher layer processing unit 101, the downlink data (the transportblock) resulting from the decoding.

The measurement unit 1059 performs downlink path loss measurement,channel measurement, and/or interference measurement from the downlinkreference signal input from the demultiplexing unit 1055, Themeasurement unit 1059 outputs, to the higher layer processing unit 101,the measurement result and CSI calculated based on the measurementresult. The measurement unit 1059 calculates a downlink channel estimatevalue from the downlink reference signal and outputs the calculateddownlink channel estimate value to the demultiplexing unit 1055.

The transmitter 107 generates the uplink reference signal in accordancewith the control signal input from the controller 103, codes andmodulates the uplink data (the transport block) input from the higherlayer processing unit 101, multiplexes the PUCCH, the PUSCH, and thegenerated uplink reference signal, and transmits a signal resulting fromthe multiplexing to the base station apparatus 3 through the transmitand/or receive antenna 109.

The coding unit 1071 codes the Uplink Control Information and the uplinkdata input from the higher layer processing unit 101. The modulationunit 1073 modulates the coded bits input from the coding unit 1071, incompliance with a modulation scheme such as BPSK, QPSK, 16 QAM, 64 QAM,or 256 QAM.

The uplink reference signal generation unit 1079 generates a sequencedetermined according to a prescribed rule (formula), based on a physicalcell identity (also referred to as a Physical Cell Identity (PCI), acell ID, or the like) for identifying the base station apparatus 3, abandwidth in which the uplink reference signal is mapped, a cyclic shiftnotified with the uplink grant, a parameter value for generation of aDMRS sequence, and the like.

Based on the information used for the scheduling of PUSCH, themultiplexing unit 1075 determines the number of PUSCH layers to bespatially multiplexed, maps multiple pieces of uplink data to betransmitted on the same PUSCH to multiple layers through Multiple InputMultiple Output Spatial Multiplexing (MIMO SM), and performs precodingon the layers.

In accordance with the control signal input from the controller 103, themultiplexing unit 1075 performs Discrete Fourier Transform (DFT) onmodulation symbols of PUSCH. The multiplexing unit 1075 multiplexesPUCCH and/or PUSCH signals and the generated uplink reference signal foreach transmit antenna port. To be more specific, the multiplexing unit1075 maps the PUCCH and/or PUSCH signals and the generated uplinkreference signal to the resource elements for each transmit antennaport.

The radio transmitting unit 1077 performs Inverse Fast Fourier Transform(IFFT) on a signal resulting from the multiplexing to perform modulationin compliance with an SC-FDMA A scheme, adds the Guard Interval to theSC-FDM-modulated SC-FDM symbol to generate a baseband digital signal,converts the baseband digital signal into an analog signal, generates anin-phase component and an orthogonal component of an intermediatefrequency from the analog signal, removes frequency componentsunnecessary for the intermediate frequency band, converts (up converts)the signal of the intermediate frequency into a signal of a highfrequency, removes unnecessary frequency components, performs poweramplification, and outputs a final result to the transmit and/or receiveantenna 109 for transmission.

FIG. 10 is a schematic block diagram illustrating a configuration of thebase station apparatus 3 according to the present embodiment. As isillustrated, the base station apparatus 3 is configured to include ahigher layer processing unit 301, a controller 303, a receiver 305, atransmitter 307, and a transmit and/or receive antenna 309. The higherlayer processing unit 301 includes a radio resource control unit 3011, ascheduling unit 3013, and a CSI report control unit 3015. The receiver305 includes a decoding unit 3051, a demodulation unit 3053, ademultiplexing unit 3055, a radio receiving unit 3057, and a measurementunit 3059. The transmitter 307 includes a coding unit 3071, a modulationunit 3073, a multiplexing unit 3075, a radio transmitting unit 3077, anda downlink reference signal generation unit 3079.

The higher layer processing unit 301 performs processing of the MediumAccess Control (MAC) layer, the Packet Data Convergence Protocol (PDCP)layer, the Radio Link Control (RLC) layer, and the Radio ResourceControl (RRC) layer. The higher layer processing unit 301 generatescontrol information for control of the receiver 305 and the transmitter307, and outputs the generated control information to the controller303.

The radio resource control unit 3011 included in the higher layerprocessing unit 301 generates, or acquires from a higher node, thedownlink data (the transport block) allocated in the downlink PDSCH,system information, the RRC message, the MAC Control Element (CE), andthe like, and outputs the result of the generation or the acquirement tothe transmitter 307, The radio resource control unit 3011 managesvarious configuration information for each of the terminal apparatuses1.

The scheduling unit 3013 included in the higher layer processing unit301 determines a frequency and a subframe to which the physical channels(PDSCH or PUSCH) are allocated, the transmission coding rate andmodulation scheme for the physical channels (PDSCH or PUSCH), thetransmit power, and the like, from the received CSI and from the channelestimate value, channel quality, or the like input from the measurementunit 3059. The scheduling unit 3013 generates the control informationfor control of the receiver 305 and the transmitter 307 in accordancewith a result of the scheduling, and outputs the generated informationto the controller 303. The scheduling unit 3013 generates theinformation (for example, the DCI format) to be used for the schedulingof the physical channels (PDSCH or PUSCH), based on the result of thescheduling.

The CSI report control unit 3015 included in the higher layer processingunit 301 controls a CSI report to be performed by the terminal apparatus1. The CSI report control unit 3015 transmits information, assumed inorder for the terminal apparatus 1 to derive RI/PMI/CQI in the CSIreference resource, for indicating various configurations, to theterminal apparatus 1 through the transmitter 307.

Based on the control information from the higher layer processing unit301, the controller 303 generates a control signal for controlling thereceiver 305 and the transmitter 307. The controller 303 outputs thegenerated control signal to the receiver 305 and the transmitter 307 tocontrol the receiver 305 and the transmitter 307.

In accordance with the control signal input from the controller 303, thereceiver 305 demultiplexes, demodulates, and decodes a reception signalreceived from the terminal apparatus 1 through the transmit and/orreceive antenna 309, and outputs inthrmation resulting from the decodingto the higher layer processing unit 301. The radio receiving unit 3057converts (down-converts) an uplink signal received through the transmitand/or receive antenna 309 into a signal of an intermediate frequency,removes unnecessary frequency components, controls the amplificationlevel in such a manner as to suitably maintain a signal level, performsorthogonal demodulation based on an in-phase component and an orthogonalcomponent of the received signal, and converts the resultingorthogonally-demodulated analog signal into a digital signal.

The radio receiving unit 3057 removes a portion corresponding to theGuard Interval (GI) from the digital signal resulting from theconversion. The radio receiving unit 3057 performs Fast FourierTransform (FFT) on the signal from which the Guard Interval has beenremoved, extracts a signal in the frequency domain, and outputs theresulting signal to the demultiplexing unit 3055.

The demultiplexing unit 1055 demultiplexes the signal input from theradio receiving unit 3057 into PUCCH, PUSCH, and the signal such as theuplink reference signal. The demultiplexing is performed based on radioresource allocation information, predetermined by the base stationapparatus 3 using the radio resource control unit 3011, that is includedin the uplink grant notified to each of the terminal apparatuses 1. Thedemultiplexing unit 3055 performs channel compensation of the PUCCH andthe PUSCH, based on the channel estimate value input from themeasurement unit 3059. The demultiplexing unit 3055 outputs an uplinkreference signal resulting from the demultiplexing, to the measurementunit 3059.

The demodulation unit 3053 performs Inverse Discrete Fourier Transform(IDFT) on the PUSCH, obtains modulation symbols, and performs receptionsignal demodulation, that is, demodulates each of the modulation symbolson the PUCCH and the PUSCH, in compliance with the modulation schemedetermined in advance, such as Binary Phase Shift Keying (BPSK), QPSK,16 QAM, 64 QAM, 256 QAM, or in compliance with the modulation schemethat the base station apparatus 3 itself notified in advance with theuplink grant to each of the terminal apparatuses 1. The demodulationunit 3053 demultiplexes the modulation symbols of multiple pieces ofuplink data transmitted on the same PUSCH by using the MIMO SM, based onthe number of spatially multiplexed sequences notified in advance withthe uplink grant to each of the terminal apparatuses 1 and informationfor indicating the precoding to be performed on the sequences.

The decoding unit 3051 decodes the coded bits of the PUCCH and thePUSCH, which have been demodulated, in compliance with a predeterminedcoding scheme by using the transmission or original coding rate that ispredetermined or notified in advance with the uplink grant to theterminal apparatus 1 by the base station apparatus 3, and outputs thedecoded uplink data and uplink control information to the higher layerprocessing unit 101. In a case that the PUSCH is retransmitted, thedecoding unit 3051 performs the decoding with the coded bits input fromthe higher layer processing unit 301 and retained in a HARQ buffer, andthe demodulated coded bits. The measurement unit 3059 measures thechannel estimate value, the channel quality, and the like, based on theuplink reference signal input from the demultiplexing unit 3055, andoutputs the measurement result to the demultiplexing unit 3055 and thehigher layer processing unit 301.

The transmitter 307 generates the downlink reference signal inaccordance with the control signal input from the controller 303, codesand modulates the downlink control information and the downlink datathat are input from the higher layer processing unit 301, multiplexesthe PDCCH, the PDSCH, and the downlink reference signal and transmits asignal resulting from the multiplexing to the terminal apparatus 1through the transmit and/or receive antenna 309 or transmits the PDCCH,the PDSCH, and the downlink reference signal to the terminal apparatus 1through the transmit and/or receive antenna 309 by using separate radioresources.

The coding unit 3071 codes the downlink control information and thedownlink data input from the higher layer processing unit 301. Themodulation unit 3073 modulates the coded bits input from the coding unit3071, in compliance with a modulation scheme such as BPSK, QPSK, 16 QAM,64 QAM, and 256 QAM.

The downlink reference signal generation unit 3079 generates, as thedownlink reference signal, a sequence known to the terminal apparatus 1,the sequence being determined in accordance with a predetermined rulebased on the physical cell identity (PCI) for identifying the basestation apparatus 3, or the like.

The multiplexing unit 3075, in accordance with the number of PDSCHlayers to be spatially multiplexed, maps one or multiple pieces ofdownlink data to be transmitted in one PDSCH to one or multiple layers,and performs preceding to the one or multiple layers. The multiplexingunit 3075 multiplexes the downlink physical channel signal and thedownlink reference signal for each transmit antenna port. Themultiplexing unit 3075 maps the downlink physical channel signal and thedownlink reference signal to the resource elements for each transmitantenna port.

The radio transmitting unit 3077 performs Inverse Fast Fourier Transform(IFFT) on the modulation symbol resulting from the multiplexing or thelike, performs the modulation in compliance with an OFDM scheme, addsthe guard interval to the OFDM-modulated OFDM symbol, generates adigital signal in a baseband, converts the digital signal in thebaseband into an analog signal, generates an in-phase component and anorthogonal component of an intermediate frequency from the analogsignal, removes frequency components unnecessary for the intermediatefrequency band, converts (up converts) the signal of the intermediatefrequency into a signal of a high frequency signal, removes unnecessaryfrequency components, performs power amplification, and outputs a finalresult. to the transmit and/or receive antenna 309 for transmission.

(1) More specifically, a terminal apparatus 1 according to a firstaspect of the present invention includes; a receiver configured toreceive a physical downlink control channel for conveying downlinkcontrol information including a first information field; and atransmitter configured to report channel state information (CSI),wherein the first information field indicates first information, thefirst information indicates one of multiple states, each of the multiplestates is associated with: a configuration related to one or multipleCSI reports; and a configuration related to one or multiple CSIresources, and the one of the multiple states is configured to beassociated with a first serving cell and a bandwidth part (BWP) of thefirst serving cell.

(2) A base station apparatus 3 according to a second aspect of thepresent invention includes; a transmitter configured to transmit aphysical downlink control channel for conveying downlink controlinformation including a first information field; and a receiverconfigured to receive a channel state information (CSI) report, whereinthe first information field indicates first information, the firstinformation indicates one of multiple states, each of the multiplestates is associated with: a configuration related to one or multipleCSI reports; and a configuration related to one or multiple CSIresources, and the one of the multiple states is configured to beassociated with a first serving cell and a bandwidth part (BWP) of thefirst serving cell.

(3) A communication method according to a third aspect of the presentinvention is a communication method for a terminal apparatus, thecommunication method including the steps of: receiving a physicaldownlink control channel for conveying downlink control informationincluding a first information field; and reporting channel stateinformation (CSI), wherein the first information field indicates firstinformation, the first information indicates one of multiple states,each of the multiple states is associated with: a configuration relatedto one or multiple CSI reports; and a configuration related to one ormultiple CSI resources, and the one of the multiple states is configuredto be associated with a first serving cell and a bandwidth part (BWP) ofthe first serving cell.

(4) A communication method according to a fourth aspect of the presentinvention is a communication method for a base station apparatus, thecommunication method including the steps of: transmitting a physicaldownlink control channel for conveying downlink control informationincluding a first information field; and reporting channel stateinformation (CSI), wherein the first information field indicates firstinformation, the first information indicates one of multiple states,each of the multiple states is associated with: a configuration relatedto one or multiple CSI reports; and a configuration related to one ormultiple CSI resources, and the one of the multiple states is configuredto be associated with a first serving cell and a bandwidth part (BWP) ofthe first serving cell.

(5) An integrated circuit according to a fifth aspect of the presentinvention is an integrated circuit mounted on a terminal apparatus, theintegrated circuit including: a receiving unit configured to receive aphysical downlink control channel (PDCCH) for conveying downlink controlinformation (DCI) including a first information field (CSI requestfield); and a transmitting unit configured to report channel stateinformation (CSI), wherein the first information field indicates firstinformation, the first information indicates one of multiple states,each of the multiple states is associated with: a configuration relatedto one or multiple CSI reports; and a configuration related to one ormultiple CSI resources, and the one of the multiple states is configuredto be associated with a first serving cell and a bandwidth part (BWP) ofthe first serving cell.

(6) An integrated circuit according to a sixth aspect of the presentinvention is an integrated circuit mounted on a base station apparatus,the integrated circuit including: a transmitting unit configured totransmit a physical downlink control channel (PDCCH) for conveyingdownlink control information (DCI) including a first information field(CSI request field); and a receiving unit configured to receive achannel state information (CSI) report, wherein the first informationfield indicates first information, the first information indicates oneof multiple states, each of the multiple states is associated with: aconfiguration related to one or multiple CSI reports; and aconfiguration related to one or multiple CSI resources, and the one ofthe multiple states is configured to be associated with a first servingcell and a bandwidth part (BWP) of the first serving cell.

A program running on an apparatus according to the present invention mayserve as a program that controls a Central Processing Unit (CPU) and thelike to cause a computer to operate in such a manner as to realize thefunctions of the above-described embodiment according to the presentinvention. Programs or the information handled by the programs aretemporarily stored in a volatile memory such as a Random Access Memory(RAM), a non-volatile memory such as a flash memory, a Hard Disk Drive(HDD), or any other storage device system.

Note that a program for realizing the functions of the embodimentaccording to the present invention may be recorded in acomputer-readable recording medium. This configuration may be realizedby causing a computer system to read the program recorded on therecording medium for execution. It is assumed that the “computer system”refers to a computer system built into the apparatuses, and the computersystem includes an operating system and hardware components such as aperipheral device. The “computer-readable recording medium” may be anyof a semiconductor recording medium, an optical recording medium, amagnetic recording medium, a medium dynamically retaining the programfor a short time, or any other computer readable recording medium.

Each functional block or various characteristics of the apparatuses usedin the above-described embodiment may be implemented or performed on anelectric circuit, for example, an integrated circuit or multipleintegrated circuits. An electric circuit designed to perform thefunctions described in the present specification may include ageneral-purpose processor, a Digital Signal Processor (DSP), anApplication Specific Integrated Circuit (ASIC), a Field ProgrammableGate Array (FPGA), or other programmable logic devices, discrete gatesor transistor logic, discrete hardware components, or a combinationthereof. The general-purpose processor may be a microprocessor or may bea processor of known type, a controller, a micro-controller, or a statemachine instead. The above-mentioned electric circuit may include adigital circuit, or may include an analog circuit, In a case that withadvances in semiconductor technology, a circuit integration technologyappears that replaces the present integrated circuits, it is alsopossible to use a new integrated circuit based on the technologyaccording to one or more aspects of the present invention.

Note that, in the embodiments according to the present invention,examples have been described in which the present invention is appliedto a communication system constituted by a base station apparatus and aterminal apparatus, but the present invention can also be applied in asystem in which terminals communicate each other such as Device toDevice (D2D).

Note that the invention of the present patent application is not limitedto the above-described embodiments. In the embodiment, apparatuses havebeen described as an example, but the invention of the presentapplication is not limited to these apparatuses, and is applicable to aterminal apparatus or a communication apparatus of a fixed-type or astationary-type electronic apparatus installed indoors or outdoors, forexample, an AV apparatus, a kitchen apparatus, a cleaning or washingmachine, an air-conditioning apparatus, office equipment, a vendingmachine, and other household apparatuses.

The embodiments of the present invention have been described in detailabove referring to the drawings, but the specific configuration is notlimited to the embodiments and includes, for example, an amendment to adesign that falls within the scope that does not depart from the gist ofthe present invention. Various modifications are possible within thescope of the present invention defined by claims, and embodiments thatare made by suitably combining technical means disclosed according tothe different embodiments are also included in the technical scope ofthe present invention. A configuration in which constituent elements,described in the respective embodiments and having mutually the sameeffects, are substituted for one another is also included in thetechnical scope of the present invention.

1-6. (canceled)
 7. A terminal device comprising: higher layer circuitryconfigured to receive first information and second information,reception circuitry configured to receive a physical downlink controlchannel (PDCCH) carrying downlink control information (DCI) including achannel state information (CSI) request field, and transmissioncircuitry configured to transmit a CSI report based on the CSI requestfield, wherein the first information indicating a plurality of CSItrigger states, the second information indicates a size NTS of the CSIrequest field in the DCI, and in a case that a quantity of the pluralityof CSI trigger states is greater than 2^(NTS)−1, each code point of theCSI request field is mapped to one of the CSI trigger states, and theone of the CSI trigger states is selected by medium access control (MAC)circuitry of the terminal device, in a case that a quantity of theplurality of CSI trigger states is less than or equal to 2^(NTS)−1 theCSI request field directly indicates one from the plurality of the CSItrigger states.
 8. The terminal device according to claim 7, wherein theMAC circuitry configured to indicate an indication for selection of theCSI trigger states, and one of the CSI trigger states corresponding to“1” in the indication is mapped to a code point in the CSI requestfield.
 9. A communication method for a terminal device, thecommunication method comprising: receiving first information and secondinformation, receiving a physical downlink control channel (PDCCH)carrying downlink control information (DCI) including a channel stateinformation (CSI) request field, and transmitting a CSI report based onthe CSI request field, wherein the first information indicating aplurality of CSI trigger states, the second information indicates a sizeNTS of the CSI request field in the DCI, and in a case that a quantityof the plurality of CSI trigger states is greater than 2^(NTS)−1, eachcode point of the CSI request field is mapped to one of the CSI triggerstates, and the one of the CSI trigger states is selected by theterminal device, in a case that a quantity of the plurality of CSItrigger states is less than or equal to 2^(NTS)−1 the CSI request fielddirectly indicates one from the plurality of the CSI trigger states. 10.A base station device comprising: higher layer circuitry configured totransmit first information and second information, transmissioncircuitry configured to transmit a physical downlink control channel(PDCCH) carrying downlink control information (DCI) including a channelstate information (CSI) request field, and reception circuitryconfigured to receive a CSI report based on the CSI request field,wherein the first information indicating a plurality of CSI triggerstates, the second information indicates a size NTS of the CSI requestfield in the DCI, and in a case that a quantity of the plurality of CSItrigger states is greater than 2^(NTS)−1, each code point of the CSIrequest field is mapped to one of the CSI trigger states, and the one ofthe CSI trigger states is selected by the terminal device, in a casethat a quantity of the plurality of CSI trigger states is less than orequal to 2^(NTS)−1, the CSI request field directly indicates one fromthe plurality of the CSI trigger states.
 11. A communication method fora base station device, the communication method comprising: transmittingfirst information and second information, transmitting a physicaldownlink control channel (PDCCH) carrying downlink control information(DCI) including a channel state information (CSI) request field, andreceiving a CSI report based on the CSI request field, wherein the firstinformation indicating a plurality of CSI trigger states, the secondinformation indicates a size NTS of the CSI request field in the DCI,and in a case that a quantity of the plurality of CSI trigger states isgreater than 2^(NTS)−1, each code point of the CSI request field ismapped to one of the CSI trigger states, and the one of the CSI triggerstates is selected by the terminal device, in a case that a quantity ofthe plurality of CSI trigger states is less than or equal to 2^(NTS)−1the CSI request field directly indicates one from the plurality of theCSI trigger states.